SU573152A1 - Device for dlagnosing heart deseases by using ultrasonic vibrations - Google Patents

Description

The device works as follows:

Generator-synchronizer 1. produces pulses with a repetition rate of 3-4 KHz with a duration of about 10 microseconds and controls impulse modulator 2, the input of which receives: generator voltage 3 of ultrasonic frequency oscillations. The output voltage of the pulse modulator 2, which is a radio pulse with a duration of 10 microseconds with a filling frequency equal to the frequencies of generator 3, excites an electroacoustic converter 4 emitting at its own resonant frequency 2.5 MHz Simultaneously with the pulses of the generator 1, the strobe pulse shaper starts, which generates a pulse with an adjustable delay time relative to the pulse of the converter 4 and controls the amplitude, the selector 6. The pulse duty cycle of the generator 1 at the selected frequency provides the necessary time interval for undistorted (without overlapping) reception of reflected echo pulses, which are then converted by converter 4, and its output voltage is amplified by high frequency amplifier 7.

The sampling of the selected echoing pulse was performed by the operator on the visual indicator 8, which is connected to the electron beam tube and the sweep generator of which is synchronized by the pulse generator 1, which ensures that the start of the sweep coincides with the pulse of the converter 4, the output voltage of the high frequency amplifier 7 and the input pulse 8 1 strobe pulse generator 5, the time delay relative to the beginning of the sweep which is chosen by the operator, is equal to the time of arrival of the selected of the echo pulse, which corresponds to the coincidence of the pointing pulses on the screen of the cathode ray tube of the indicator 8. During the time of the strobe pulse action, the selector 6 is open and, through Hi-i.ro, the output voltage of the high-frequency amplifier 7 is fed to the inputs of the amplitude and phase detectors 9 and 10, such The selective gating circuit provides a separate assessment of the characteristics of each of the echoes selected for the study. The width of the strobe pulse is selected from the condition of exclusion of the progress through the selector 6 of other echo pulses and ensuring that it coincides with all temporary changes in the arrival of the selected echo ig.-etulse due to displacements

the spatial position is reflected to it in all phases of the cardiac cycle, From the output of the amplitude detector 9, the detected pulse transmitted through the selector 6 is fed to the input of the reflector cardioelement measurement unit 13 (offset) offset, the output voltage of the unit 13 is a time type converter - voltage, is a function of the time of arrival of the echo pulse selected by the selector b relative to the beginning of the radiation of converter 4, and its change characterizes the change in the distance to the reflecting target, i.e. changing her path of movement

The second input of the phase detector 10 receives the voltage of the generator 3, which is a coherent signal for measuring the phase shift of the pulse selected by the selector 6. In this case, the envelope of the pulses at the output of the phase detector 10 is a sinusoidal oscillation of the Doppler frequency and, accordingly, is proportional to the speed of the located target, from which this reflected echo pulse is received. In this connection, the output voltage of the phase detector 10 is fed to the input unit 11 of the Doppler separation unit. frequency, and its input signal, to the input of speed measurement unit 12, which is a voltage-to-voltage type converter.

The output voltage of the speed measurement unit 12 is proportional to the instantaneous values of the frequency of the output Doppler signal, and the variation of its change is the nature of the change in the speed of the located element during the cardiac cycle. At the same time, the speed of the Doppler frequency deviation, i.e. changing the output voltage of the block 12 will characterize the amount of mechanical acceleration of the movement of the reflective cardioelement.

To measure it from the output of the speed measurement unit 12, the voltage is fed to the input of the acceleration measurement unit 14, which is a differentiator and allows to obtain the first derivative of the measurement envelope of the output voltage of the moving target velocity measuring unit - frequency-voltage transducer.

The proposed device is a coherent-pulse bio-echo sounder, which turns into a conventional Doppler, if you remove a 2p pulsed modulator from it and into a conventional pulsed modulator.

if the voltage from the generator output 3 ultrasonic frequency oscillations is not supplied to the second input of the phase detector 10. The sonar allows you to measure the radial values of the path, speed, and acceleration of the locomotion of the heart.

The output voltages of the path measurement unit 13, the speed measurement unit 12 and the acceleration measurement unit 14 are received in pairs at the inputs of dividers 15-20, each of which performs the operation of dividing two input values specified as voltages equal to the values of the path, speed and acceleration of motion cardioelement. Dividers 15–20 are operational amplifiers, the output voltages of which are proportional to the partial ratio of the input signal values, one of which is fed to the input of the divider, and the second to the input of the dividend.

Thus, the output voltages of the dividers 15–20 are a set of normalized parameters of the mechanical and mechanical activity of the heart, representing the ratio of the absolute values of the path, speed and acceleration of the movement of the locatable element and are fed to the recording device 21.

Such an embodiment of the device eliminates the influence on the measurement results of the varying angle between the directions of propagation of ultrasonic oscillations and the movement of the locomotor site of the heart due to its rotational displacements and provides a set of normalized parameters for estimating the energy-mechanical activity of the heart in the form of specified ratios of the measured path, velocity and accelerate movement.

Claims (1)

1. Copyright certificate №278010, M.cl. A 61 B 10/00, 1970.